Metamath Proof Explorer


Theorem oppcuprcl4

Description: Reverse closure for the class of universal property in opposite categories. (Contributed by Zhi Wang, 4-Nov-2025)

Ref Expression
Hypotheses oppcuprcl2.x
|- ( ph -> X ( <. F , G >. ( O UP P ) W ) M )
oppcuprcl4.o
|- O = ( oppCat ` D )
oppcuprcl4.b
|- B = ( Base ` D )
Assertion oppcuprcl4
|- ( ph -> X e. B )

Proof

Step Hyp Ref Expression
1 oppcuprcl2.x
 |-  ( ph -> X ( <. F , G >. ( O UP P ) W ) M )
2 oppcuprcl4.o
 |-  O = ( oppCat ` D )
3 oppcuprcl4.b
 |-  B = ( Base ` D )
4 2 3 oppcbas
 |-  B = ( Base ` O )
5 1 4 uprcl4
 |-  ( ph -> X e. B )